JPS6068585A - Electrode unit for arc furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrode apparatus for an electric arc furnace. More particularly, the present invention is an electrode arrangement for an electric arc furnace having a metal shaft comprising a water cooling system and a clamping zone, the metal shaft being surrounded by a protective jacket positioned below the clamping zone. The present invention further relates to an electrode device for an arc furnace, the device including a consumable active part, the metal, the shaft and the active part being electrically interconnected by contact, a-z means.

BACKGROUND OF THE INVENTION Electrodes for arc furnaces similar to those described above are disclosed in European patent application no.
The electrode described in this patent application, known by No. 0682, consists of a gold plate connected to the active part by a nipple;
1. It has a protective jacket (consisting of a shaft and surrounding the metal shaft 171).

U.S. Pat. has been done. This electric wire (・υ) must be directly clamped on the metal shaft.

British Special Issue No. 71 No. 2037549 consists of two water pipes surrounded by a steel jacket made from three coaxial rings, i.e. two annular spaces forming part of the water cooling circuit. The disclosed jacket surrounds the inner/split over substantially its entire length, and the electric guard is clamped with this jacket.

According to European Patent Application No. 50682? Ilf'7
ji has very good operating characteristics and is already used in many arc furnaces.Today, the main motivation for the development of water-cooled R7 is to reduce steel production costs. Therefore, new iiJ capabilities are desired which will further save costs.For this reason, European patent application no. Further efforts are being made to reduce the maintenance costs of known electric power plants.

Electric power according to U.S. Patent No. 4,121,042! '7d
j, whose metal part consists of a single integral element, so that the circumference ■1 metal wall is mechanically arced or weighed 1 scrap piece? If it is damaged by an N-strike, it has the disadvantage of having to disassemble the entire unit and reassemble it after replacing the damaged parts.

The electrode described in GB 2037549 has a steel jacket which is also connected to the internal cooling tube of the electrode and is therefore not replaceable l/).

Furthermore, there is the disadvantage that the clamping of the electric cable takes place in its jacket. This is because, for this purpose, the jacket must have a very high mechanical strength in order to absorb clamping forces of the order of 20 to 40 tons (17).

U.S. Pat. No. 4,291,190 discloses in its preamble an electric boulder, which consists of several water tubes placed at the lower end of its electrode holder for cooling the nipple. This water pipe is embedded in a 1:4 cylinder of 1 shochu size, and this cylinder is further surrounded by a hollow steel cylinder that fits with the cylinder.In this patent,
Water by the metal cylinder〇 or the fireproof cylinder)
It is disclosed that the tube is electrically insulated from electrical currents conducted therein. However, this fireproof cylinder
It is thought that the metal cylinder is sufficiently cooled by heat conduction to the water tube.

It is well known that good thermal conductors are also good electrical conductors and vice versa. Therefore, the type 4i has the disadvantage that the electrical insulation of the metal cylinder from the water pipe is not perfect and the effect becomes stronger as the temperature increases, if the metal cylinder is to be sufficiently cooled. There is. However, it is very important to electrically insulate the metal sheath from all parts that carry the electrode potential. This is because non-insulated metal sheathing is exposed to the formation of electrical arcs between it and scrap in close proximity to it and is therefore rapidly damaged.

OBJECTS OF THE INVENTION The object of the present invention is to improve the electrode device described above and to reduce its wholesale and carrying costs, as well as to avoid the disadvantages mentioned above.

Another object of the present invention is to provide an electrode holder for an arc furnace that is electrically insulated from the metal sheath of the electrode holder or other electrode portions that hold an electric potential.

Furthermore, another object of the invention is to provide a protective sheath surrounding the electrode hole that has a long service life and is easy to remove in case of wear.

SUMMARY OF THE INVENTIONAccording to the present invention, these objectives are such that a protective jacket is installed between the rX3 cooling system, the protective jacket and the gold LDS shaft, whereby
and the shaft are electrically insulated from each other by a refractory layer, the refractory layer being a protective jacket, cooled by a 1X cooling system, and the jacket is electrically insulated from the metal shaft.
- It can be removed from an electrode device such as that shown in the preface, which is removably arranged at the top.

The present invention provides a protective metal jacket that is exposed to the inside of an arc furnace, and that separates the jacket from electrically conductive parts by 4[L].
This is based on the knowledge that the increased conductivity of refractory feedstuffs causes them to gradually lose their electrical insulating properties as they are heated.

It is therefore necessary, as is known, to provide a water cooling device that cools the metal jacket and maintains the temperature of the insulating material low enough to ensure its good insulating properties.

In for the metal shaft and protective jacket can be freely selected depending on their properties and purpose. The metal shaft has the primary purpose of transmitting the current to the active part with as few losses as possible and, furthermore, ensuring a good cooling effect for the active part. In both cases, the use of copper is 411', which is recommended.

However, the metal jacket has a high AMI! It must have good mechanical stability as well. Furthermore, since the jacket is extinguished and must be replaced, it should be cost-effective. For this purpose, steel is the most popular material that provides the necessary technical properties at an acceptable price.

DESCRIPTION OF THE PREFERRED EMBODIMENT According to one embodiment of the invention, the /-'l of the protective jacket
It can be connected in series to the cooling system of the shaft. Other connections are also possible.

For example, the cooling medium can first flow through the protective jacket and then into the metal shaft or vice versa, or the metal shaft can be constructed from several sections and the protective jacket can be placed between the two sections of the metal shaft with respect to the flow of the cooling medium. You can also place it in

According to a preferred embodiment of the invention, the protective jacket can be formed by a spirally, tightly wound coil system in front of the metal. This type of protective jacket allows for particularly simple manufacture and is easy to repair in case of damage during driving.

In one embodiment of an electric (one-meter) device when a protective jacket is placed between two sections of a metal shaft with respect to the flow of the cooling medium, the metal shaft consists of a central tube and an outer tube surrounding the central tube, with both tubes An annular space can be formed between the two tubes, which is divided by a plate connected to the two tubes into an upper and a lower annular space section with one novel corresponding substantially to the height of the protective jacket. Each of these annular space sections is provided with a connection socket through which it can be connected to the interior of the protective jacket.

The protective jacket is arranged around the metal shaft in an electrically insulated manner, and the connection of the coupling socket can be made via an electrically insulating intermediate part, the electrically insulating intermediate layer being a ceramic mat. Alternatively, it can be made of blown ceramic.

In embodiments of the invention, the cooling medium used in the metal shaft may be separate from the cooling medium in the protection jacket. For example, if a gold Di'v shaft is cooled with water,
On the other hand, the protective jacket can be cooled with dirt, for example water vapor. This has the advantage that no water can enter the arc force in the event that the protective jacket is damaged.For this purpose, the protective jacket is Become.

In order to improve the protective properties of the protective jacket, it can also consist of an outer layer of sprayed or laminated refractory material, ceramic and/or slag, at least in its lower region.

The present invention will be explained in more detail with reference to specific examples shown in the drawings in Appendix A.

In the drawings, FIG. 1 shows an electrode of the invention having a cooling water circuit within the protective jacket, which cooling water circuit is connected in series with the cooling circuit of the fish urine shaft.

FIG. 2 shows an electrode arrangement similar to that of FIG.
It has a protective jacket that is independent of the column system.

FIG. 3 shows another embodiment of the invention in which a /9 coil is embedded in a refractory cylinder which also has several graphic eye l-') rings across its lower region. surrounded by

FIG. 4 shows an embodiment of the invention consisting of a protective jacket formed from two coaxial cylinders with internal water circuits.

FIG. 1 shows a metal shaft 1 of an electrode for a coupled arc furnace,
It is connected by a threaded nipple 2 to the active part 3 of the graph-j'ite (only the connecting part is shown). The metal shaft 1 consists of a central tube 4 and an outer body 5 arranged coaxially around the tube 4.

An annular space is formed between the tubes 4 and 5 and is sealed off by an annular disc 7 except at its top or outlet socket. At its lower end 28, the metal shaft 1 widens, opens downwards and comprises a hole with an internal thread 8, into which the nipple 2 is screwed. The [ζi, lAi part 28 of the metal shaft also has an external thread (not shown), onto which a ring 29 of the shape JfT+ffi force opening of graphite-containing HII is screwed.

Alternatively, instead of a nipple, the connection of the metal shaft 1 with the active part 3 can be effected by ramping means, as described, for example, in Yaw I] Tsuba Special Application No. 0053200.

The central and external tubes, in particular the annular space between them, are used for supplying and discharging a cooling medium, e.g. water, which enters the central tube according to the arrows shown and passes through the lower sieve of the metal shaft: It changes direction at the end and then ascends through the annular space and is extracted from the metal shaft through the outlet socket.

The annular space formed by the medium-fired tube and the external equipment is divided into an L annular space 9 and a lower annular space 1o by an annular disk 11 that is in contact with the two tubes at f8.

12. The lower annular space 1o is formed by the lower surface of the annular disc 11 near its upper end.
7'l,...'The two-part annular space 9 enters near its bottom 1'
It has a socket 13.

The protective jacket 14 consists of a metal tube system 15 extending helically around the four sides of the outer tube 5 and is arranged around an area substantially corresponding to the lower annular space 10 of the metal shaft 1 .

The metal tubing system can consist of a metal tube coiled by a double hanging method, the beginning and end of which can be placed on top of a helical coil, or can be made from a plurality of parallel loops. I can do it.

The beginning and end of the metal tube 15 have connecting branches 16 and 17 which connect to the outlets of the annular spaces 9 and 10 and to the artificial sockets 12 and 13, as shown.

Thus, after changing direction at the lowest region of the metal shaft, the cooling water flows through the lower annular region 10 to the annular disk 1.
1, exits the annular space through the outlet socket 12 and reaches the protective jacket 14, in which it flows according to the red stamp from the top to the bottom and then to the top again, where the connecting branch pipe It exits the jacket through 17, enters the upper annular space 9 through the prosthetic socket 13, and then exits from this space through the outlet socket 6.

The protective jacket 14 connects the inlet or outlet sockets 12 and 1.
3 and connecting branches 16 and 17 are connected to the metal shaft, so that the jacket can be separated in a simple way, such as by separating such water connections.

1. The entire zeta jacket can then be completely removed for repair or replacement by pulling it vertically away from the entire urine shaft 1.

The water-cooled jacket has two functions: one is to shield the copper metal shaft from the 1η: tangential generation of arc inside the arc furnace, especially at the Another feature is the intermediate refractory material 43 i'
On the contrary, it has to maintain a temperature of 7A at which it loses its electrical insulating properties.

Keeping the jacket electrically insulated from the metal shaft prevents attacks on the jacket from scrap.
This is very important to avoid the formation of arcs.

In order to improve the protective properties, the protective jacket 4 can also be further protected at its ends by refractory materials, ceramics and/or slags.

A refractory material 43, as described above, is placed between the metal shaft and the jacket 14, and is placed at the lower part of the jacket where the shaft contacts the nipple area to hold the jacket there. Maintain insulation from The water connection part between the jacket and the metal shaft consists of electrically insulating intermediate parts 44 and 44, which complete the electrical isolation between the metal shaft and the jacket. The refractory material can also be spread near the lower end of the jacket to ensure safe insulation in that area even in the event of slag splashes that could frizz the insulation gap with the conductive slag.

By these means it is possible to disconnect the electrical potential of the protective jacket 14Q from the metal shaft 1 and to maintain it at ground potential. This method makes it possible to prevent arcing from the sides between the jacket and the scrap pieces that are present at similar ground potential in the furnace.

The uppermost area of the shaft I, surrounded by a protective jacket 14, is used for applying an electrode holder, which can also make electrical connections.

Gold L [Reinforcement ribs 24 extending paraxially or radially within the clamping zone 18 of the shaft 1
or is provided between the outer tube 5 and the central tube 4.

This reinforcement rib 24 has the purpose of preventing the outer tube 5 from being deformed if pressure is applied to it by the clamping jaws (not shown).

FIG. 2 shows an arc electrode arrangement similar to the embodiment shown in FIG. 1, but the protective jacket 14 has a cooling circuit that is independent of the cooling system of the metal shaft.

Since the other parts are as already described with respect to FIG. 1, only this difference will be explained below.

As in FIG.
1 through which the cooling medium can be supplied and discharged, respectively.

These branches or conduits 20 and 21 for the cooling medium extend in such a way that they do not interfere with the clamping of the electrodes, i.e. below the clamping area 18 of the electrodes they extend away from the metal shaft. .

Also, in this case, the protective jacket] 4 is electrically insulated from the metal shaft by a fire-resistant layer 43.

Due to the independence of the supply of the cooling medium to the protective jacket and the supply of said medium to the metal shaft, there is the possibility of cooling this protective jacket with a different cooling medium than the metal jar 71-.

For example, the protective jacket can be cooled with water vapor or other gases, so that even in the event of a leakage of the protective jacket, gas rather than liquid will reach the furnace chamber or the melt. This reduces and prevents the problem of possible water bursting inside the furnace.

FIG. 3 shows another embodiment of the invention in which the protective jacket 14 consists of a coil formed by a metal tube 15, which coil is embedded in a cylinder of refractory lining surrounding the metal shaft 1. There is.

In this case, such a device is completely surrounded by a metal tube 15 or refractory material, so that this layer is therefore electrically insulated from the metal shaft.

The metal tube 15' has a connecting branch 20 which can supply the cooling medium to a protective jacket independent of the cooling system of the shaft.
and starving 21.

The protective jacket 14 may be directly exposed to the furnace environment and possible splashing, or it may be further protected by a ring 23 of graphite-containing material.

FIG. 4 does not show a further embodiment of the invention corresponding to Gold X Shaft 1 or the shafts of FIGS. 2 and 3. Electric (4
The metal shaft of the holder 14 is connected to the active part 40 by a threaded nipple 39.

At the top of the joint shaft B, an inlet socket l-41ji6 and an outlet socket 42 for cooling water are connected to the water supply pipes 34 and 34. These supply tubes also connect with flexible water hoses 36 and 36, thereby fluidly connecting cooling water conduits 32 and 32 thereto. Conduits 32 and 32 lead to a jacket 30 surrounding the lower region of the metal shaft. Due to a cylindrical refractory layer 43 placed between the metal shaft and the jacket 14 and two other similar rings 33 and 35, each of smaller axial dimension than the layer 43, the ducts 32 and 32 are made of metal. electrically isolated from the shaft. Mechanical identification of the conduits 32 and 32 is provided by a holder bar 37.
This bar is fixed to the metal shaft via an insulating pad 38 using a port or the like to completely insulate the bar from the metal shaft. At the lower end of the jacket 14, a resistant material 43 extends between the active part and the jacket (and advantageously extends to the outside of the jacket) and extends at least the low range of the jacket. Thus, slack splashes that could bridge the active part with the jacket cannot create an electrical connection between them.

Although one or more preferred embodiments of the present invention have been described, the present invention is not limited thereto. For example, the shape of the protective jacket, such as the spiral type, is just one example that is advantageous for manufacturing; various other shapes of water circuits can be considered, for example, the cooling water can be routed to one mound-shaped space. Three coaxial tubes forming an external and internal annular space such that the flow is downward in one case and upward in the other annular space, or two with baffles between their cylinders such that the cooling medium is conveyed in a meandering circuit. The same pongee cylinder is mentioned.

Alternatively, a plurality of paraxially extending tubes may be provided, and the chain tubes may be connected to each other in pairs at their lower ends in a continuous manner to form a water circuit using these pairs of tubes. Can be connected in series or in parallel.

Similarly, the invention is not limited to material selection.

Copper or steel are examples only, economical and technical? Many metal materials AI can be used without departing from the spirit of the present invention under consideration of RLE.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of one specific side of the electric motor (vehicle) of the present invention having a cooling water circulation path inside the protective jacket, and FIG.
Figures 1 to 4 are schematic vertical cross-sectional views of the body side of the modified aspect of the present invention. In the drawings, main symbols mean the following. 1... Metal shaft , 2... threaded nipple, 3.
...Active part, 14...Protective jacket, ]5...
Pipe, 43... Surface flammability R stand. Patent Applicant Arc Technologies Cislano Fu,
Limited representative patent attorney Aoyama 1 light h2 drawings,) 2 (no changes to the content) Continuation of page 1 1. Erlange, Federal Republic of Stoss - Stoitatsuba, Am Hosgraben 11, Schheich Nuremberg, Federal Republic of the Soviet Union, Henterlase 1 Procedural Amendment (0 Separate September 1980 10 Indication of Case 1989 Patent Application No. 169883 No. 2 Name of the invention 11 Electrode device for arc furnace Knee 3 Relationship with the case Patent applicant Limited 4 agent name Patent attorney Qi',!l・l) r:i Yama 葆 (
” or 2 people 5 Yusho orders with [” voluntarily

Claims (1)

[Claims] (1) Consisting of a water cooling system and a clamping area.
An electrode device for an electric arc furnace having a metal shaft, the metal shaft being surrounded by a protective jacket positioned below the clamping area, and further containing a consumable active part, the metal shaft being surrounded by a protective jacket disposed below the clamping area; The active portions are connected to each other pneumatically (;1) by contact means;
A protective jacket (14) is a cooling system, consisting of a refractory layer (43) placed between the cooling jacket (14) and the metal shaft (1), whereby the jacket and the shaft or each other's electricity is cut off,
1 cough 1 mI fire layer (43) is the protective jacket 1-(14
), and the arc furnace is cooled by the cooling system of the arc reactor, which is cooled by the cooling system of the arc reactor, which is cooled by the cooling system of the arc furnace, and the jugette is attached and detached onto the pub shaft (1). 2) The metal shirt eye 1) consists of a metal tube (1).
5, 15) is made of steel. [3] Cooling system (4, 9) for the metal shaft (1)
, 10) is the cooling system of the protective jacket) (14,)
(4) The protective jacket (14) is connected in series to the coil tube (15, 15) of the above paragraph (1) or (2). Said number being formed (
Either one of the electric currents ([υζ device. The official shaft (1
] Two coaxial ω Yu genus arranged around the! iTi, or form two coaxial j'W:i-shaped spaces between them, and in one of the spaces, the cooling medium is directed in one direction,
The electrode device according to any one of items (1) to (3) above, consisting of three identical 1t11 cylinders, the other of which flows in two directions. (6) The metal shaft (1) consists of a central tube (4) and an outer tube [51] which connects the medium-fired tube (4), with an annular space between the two tubes (4, 5). (9,10) is formed,
The annular space (9, 10) is connected to the two tubes (4, 5) by means of a plate (11) which provides a protective jacket (14).
into an upper and lower annular space section (9, 10) at a level substantially corresponding to the height of the annular space section (9 or 10), and a socket for connecting the upper and lower annular space section (9 or 10) (12, 13). The electrode device according to any one of the preceding clauses (1) to (5), which is connected to the cooling system of the protective jacket (14) by means of a cooling system. (7) The protective jacket (14) is arranged around the metal shaft (1) in an electrically insulating manner, and the mechanical connection of the cooling system of the protective jacket (14) to the metal shaft (1) is ensured. and/or the DU by means of electrically insulating intermediate parts (44, 38).
The electrode device according to any one of items (1) to (6) above. (8) The insulating i fire-resistant layer (43) is a jacket) (14)
The electrode device according to any one of clauses (1) to (7) above, extending around the lower end of the electrode device. (9) The cooling system of the protective jacket (14) has supply and discharge conduits (20, 21) for the cooling medium, which conduits (20, 21) are independent of the cooling system of the metal shaft (1). The electrode device according to any one of the above items (1]-f5). (10) said protective jacket (14) comprises an outer layer (22) of sprayed or laminated refractory material, ceramics and/or slag covering at least a lower portion of said jacket (14); The electrode device according to any one of items (1) to (9). (11) The electronic@A device according to item (10) above, wherein the protective jacket (14) is surrounded by a graphite-containing ring (23). (12) The electrode and device according to the fi+ term, wherein a paraxially extending reinforcing rib (24) is arranged between the central tube (4) and the outer tube (5) in the clamping region (18).